On April 1, 2015, all of Nova Scotia's regional health authorities combined to form the Nova Scotia Health Authority. For the timebeing, former individual authorities continue to maintain their own websites.
Registries can be a great source of information. They usually produce annual statistics but are also often willing to answer specific questions from members of the public if they have data available:
Some subject headings to search in the library catalog:
Also look under a specific topic or disease with subheadings Nova Scotia and/or statistics. It may also be useful to search using a broader geographic area eg Health surveys--Canada, resources found this way will generally provide provincial comparisons.